#include "fs.h"
#include "initrd.h"
#include "util.h"

initrd_header_t *initrd_header;
initrd_file_header_t *file_headers;
fs_node_t *initrd_root;
fs_node_t *initrd_dev;
fs_node_t *root_nodes;
int nroot_nodes;

struct dirent dirent;

static unsigned int initrd_read(fs_node_t *node, unsigned int offset, unsigned int size, unsigned char *buf)
{
	initrd_file_header_t header = file_headers[node->inode];
	if(offset > header.length)
		return 0;
	if(offset + size > header.length)
		size = header.length - offset;
	memcpy(buf, (unsigned char*)(header.offset+offset), size);
	return size;
}

static struct dirent *initrd_readdir(fs_node_t *node, unsigned int index)
{
	if(node == initrd_root && index == 0)
	{
		strcpy(dirent.name, "dev");
		dirent.name[3] = 0;
		dirent.ino = 0;
		return &dirent;
	}
	
	if(index - 1 >= nroot_nodes)
		return 0;
	
	strcpy(dirent.name, root_nodes[index-1].name);
	dirent.name[strlen(root_nodes[index - 1].name)] = 0;
	dirent.ino = root_nodes[index - 1].inode;
	return & dirent;
}

static fs_node_t *initrd_finddir(fs_node_t *node, char *name)
{
	if(node == initrd_root && !strcmp(name, "dev"))
		return initrd_dev;
	int i;
	for(i = 0; i < nroot_nodes; i++)
		if(!strcmp(name, root_nodes[i].name))
			return &root_nodes[i];
	return 0;
}

fs_node_t *initialize_initrd(unsigned int loc)
{
	initrd_header = (initrd_header_t *)loc;
	file_headers = (initrd_file_header_t *)(loc + sizeof(initrd_header_t));
	
	// create / initialize root directory
	initrd_root = (fs_node_t*)kmalloc(sizeof(fs_node_t));
	strcpy(initrd_root->name, "initrd");
	initrd_root->mask = initrd_root->uid = initrd_root->gid = initrd_root->inode = initrd_root->length = 0;
	initrd_root->flags = FS_DIRECTORY;
	initrd_root->read = 0;
	initrd_root->write = 0;
	initrd_root->open = 0;
	initrd_root->close = 0;
	initrd_root->readdir = &initrd_readdir;
	initrd_root->finddir = &initrd_finddir;
	initrd_root->ptr = 0;
	initrd_root->impl = 0;
	
	// initialize the /dev directory
	initrd_dev = (fs_node_t*)kmalloc(sizeof(fs_node_t));
	strcpy(initrd_dev->name, "dev");
	initrd_dev->mask = initrd_dev->uid = initrd_dev->gid = initrd_dev->inode = initrd_dev->length = 0;
	initrd_dev->flags = FS_DIRECTORY;
	initrd_dev->read = 0;
	initrd_dev->write = 0;
	initrd_dev->open = 0;
	initrd_dev->close = 0;
	initrd_dev->readdir = &initrd_readdir;
	initrd_dev->finddir = &initrd_finddir;
	initrd_dev->ptr = 0;
	initrd_dev->impl = 0; 
	
	root_nodes = (fs_node_t*)kmalloc(sizeof(fs_node_t*) * initrd_header->nfiles);
	nroot_nodes = initrd_header->nfiles;
	
	
	int i;
	for(i = 0; i < initrd_header->nfiles; i++)
	{
		file_headers[i].offset += loc;
		strcpy(root_nodes[i].name, &file_headers[i].name);
		root_nodes[i].mask = root_nodes[i].uid = root_nodes[i].gid = 0;
		root_nodes[i].length = file_headers[i].length;
		root_nodes[i].inode = i;
		root_nodes[i].flags = FS_FILE;
		root_nodes[i].read = &initrd_read;
		root_nodes[i].write = 0;
		root_nodes[i].readdir = 0;
		root_nodes[i].finddir = 0;
		root_nodes[i].open = 0;
		root_nodes[i].close = 0;
		root_nodes[i].impl = 0;
	}
	return initrd_root;
}

